Other Parts Discussed in Thread: TDA4VM
Hi.
I'm sending CAN messages via MCU_MCAN_0 with SocketCAN.
write() is blocked within 10 ~ 20 minutes after starting it
I can see "Resource temporarily unavailable" when I set sockopt to SO_SNDTIMEO.
I couldn't have seen this error at PSDK6.2.
I'm using PSDK7.1.
Regards
Dongwon Choi
Hi Karan.
1) PSR register
I have attached the MCU_MCAN0_CFG register file that is exported with CCS.
521177 13 R MCU_MCAN0_CFG_MCAN_CREL 0x0000000B 0x32380608 R MCU_MCAN0_CFG_MCAN_ENDN 0x0000000B 0x87654321 R MCU_MCAN0_CFG_MCAN_DBTP 0x0000000B 0x00000A33 R MCU_MCAN0_CFG_MCAN_TEST 0x0000000B 0x00000080 R MCU_MCAN0_CFG_MCAN_RWD 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_CCCR 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_NBTP 0x0000000B 0x00008A13 R MCU_MCAN0_CFG_MCAN_TSCC 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_TSCV 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_TOCC 0x0000000B 0xFFFF0000 R MCU_MCAN0_CFG_MCAN_TOCV 0x0000000B 0x0000FFFF R MCU_MCAN0_CFG_MCAN_ECR 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_PSR 0x0000000B 0x00000708 R MCU_MCAN0_CFG_MCAN_TDCR 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_IR 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_IE 0x0000000B 0x27FFFFFF R MCU_MCAN0_CFG_MCAN_ILS 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_ILE 0x0000000B 0x00000001 R MCU_MCAN0_CFG_MCAN_GFC 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_SIDFC 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_XIDFC 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_XIDAM 0x0000000B 0x1FFFFFFF R MCU_MCAN0_CFG_MCAN_HPMS 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_NDAT1 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_NDAT2 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_RXF0C 0x0000000B 0x00200000 R MCU_MCAN0_CFG_MCAN_RXF0S 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_RXF0A 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_RXBC 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_RXF1C 0x0000000B 0x00000900 R MCU_MCAN0_CFG_MCAN_RXF1S 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_RXF1A 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_RXESC 0x0000000B 0x00000777 R MCU_MCAN0_CFG_MCAN_TXBC 0x0000000B 0x01000908 R MCU_MCAN0_CFG_MCAN_TXFQS 0x0000000B 0x00000001 R MCU_MCAN0_CFG_MCAN_TXESC 0x0000000B 0x00000007 R MCU_MCAN0_CFG_MCAN_TXBRP 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_TXBAR 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_TXBCR 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_TXBTO 0x0000000B 0x00000001 R MCU_MCAN0_CFG_MCAN_TXBCF 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_TXBTIE 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_TXBCIE 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_TXEFC 0x0000000B 0x00010900 R MCU_MCAN0_CFG_MCAN_TXEFS 0x0000000B 0x00000000 R MCU_MCAN0_CFG_MCAN_TXEFA 0x0000000B 0x00000000
PSR register is same with read by devmem2 command.
2) ip setting is same as you mentioned.
ip link set can0 type can bitrate 500000
ip link set can0 txqueuelen 1024
ip link set can0 up
Regards
Dongwon Choi
Hi Karan.
cangen is not waiting for receiving message.
As I mentioned, I was monitoring incoming CAN message with CANape.
CAN messages from cangen was just stopped such as below.
nbytes = write(s, &frame, mtu); (line 492 of cangen.c)
write() doesn't return any error value when this issue is occurred.
It is blocked forever if it is not set to non-blocking mode.
(it is set to blocking mode at cangen)
This is the same problem of my application.
I add the below codes to set SO_SNDTIMEO for finding out error code.
timeout.tv_sec = 3;
timeout.tv_usec = 0;
if (setsockopt (hdl->can_sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout, sizeof(timeout)) < 0) {
KERNEL_PRINTF(" #ERROR : Can't socket SNDTIMEO \n");
}
/* send a CAN frame */
can_send_len = write(hdl->can_sock, &frame, sizeof(struct can_frame));
if (can_send_len <= 0) {
perror("#ERROR : Can't write CAN socket");
KERNEL_PRINTF(" #ERROR : Can't write CAN socket [%d]\n",can_send_len);
return -1;
}
Then, write() returns EAGIN and Resource temporarily unavailable is printed.
Regards
Dongwon Choi
Hi Karan.
cangen is not waiting for receiving message.
As I mentioned, I was monitoring incoming CAN message with CANape.
CAN messages from cangen was just stopped such as below.
nbytes = write(s, &frame, mtu); (line 492 of cangen.c)
write() doesn't return any error value when this issue is occurred.
It is blocked forever if it is not set to non-blocking mode.
(it is set to blocking mode at cangen)
This is the same problem of my application.
I add the below codes to set SO_SNDTIMEO for finding out error code.
timeout.tv_sec = 3;
timeout.tv_usec = 0;
if (setsockopt (hdl->can_sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout, sizeof(timeout)) < 0) {
KERNEL_PRINTF(" #ERROR : Can't socket SNDTIMEO \n");
}
/* send a CAN frame */
can_send_len = write(hdl->can_sock, &frame, sizeof(struct can_frame));
if (can_send_len <= 0) {
perror("#ERROR : Can't write CAN socket");
KERNEL_PRINTF(" #ERROR : Can't write CAN socket [%d]\n",can_send_len);
return -1;
}
Then, write() returns EAGIN and Resource temporarily unavailable is printed.
Regards
Dongwon Choi
Hi Dongwon Choi,
I ran this test almost 30mins and did not see an issue. See below screen:
Another thing to note is that even when you hang, you never get a protocol error. The error where write() returns EAGIN and Resource temporarily unavailable is printed - this may hence purely be a socket related error.
There was however a case the other try where my A72 somehow hanged when running both together, I don't think that is what you observed.
I remember from your initial response that you never saw such an issue with SDK6.2, if this was due to excess load on A72 should this now be reproducible using the commands set as below?
sudo stress-ng --cpu 1 --timeout 0 & (note, I changed the timeout to 0 so that it runs indefinitely)
ip link set can0 type can bitrate 500000
ip link set can0 txqueuelen 1024
ip link set can0 up
cangen can0 -g 0
Regards
Karan
Hi Karan.
I have tested additinal tests for this problem.
Please refer to the below test result.
-------------------------------------------------------------------------------------------------------------------
cansend Use case
cansend test what you mentioned.
1. cansend test (1)
The problem is reproduced, but error code is different.
ip link set can0 type can bitrate 500000
ip link set can0 txqueuelen 1024
ip link set can0 up
sudo stress-ng --cpu 2 --timeout 0 &
root@j7-evm:~# date
Fri Jul 9 12:16:57 UTC 2021
root@j7-evm:~# while true; do /sd/can-utils/cansend can0 123#0011
done
time: 14:14:54
write: No such file or directory
2. cansend test (2)
I ran same test again.
The same problem is not reproduced for about 8 hours more.
-------------------------------------------------------------------------------------------------------------------
Camera Use case
I have tested some test cases after adding delay with SV's camera usecase.
58 CAN messages are sending at every frame.
I can find out the reproduce rate is changed when I add some delays after write().
However I don't understand why this issue is happened.
The CAN bitrate is set to 500K bps.
58 can messages x 8bytes x 8 x 30(fps) = about 108K(per 1sec)
It is not out of range.
Additionally, adding delay makes total performance(as processing time) low than before.
Please let me know if you have any guidance for avoiding this problem without adding delays.
1. changing the order of creation of socket.
[Test Result]
Start 2:59
Error 3:07
#ERROR : Can't write CAN socket: No buffer space available
oz_can_write_frame:115: #ERROR : Can't write CAN socket [-1]
===========================================================================
2. 1 milisecond sleep at every frame
I added 1 msec dealy after write() is called
Start 3:12
5:00
not reproduced
===========================================================================
3. 1 msec delay per 10 CAN messages
Start 5:07
Error 5:10
#ERROR : Can't write CAN socket: No buffer space available
oz_can_write_frame:115: #ERROR : Can't write CAN socket [-1]
===========================================================================
4. 150 micro seconds delay at every frame
Strat 6:19
8:00
not reproduced
===========================================================================
Regards
Dongwon Choi